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A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is constructed from thin plastic or other non metallic materials (usually a used plastic soft drink bottle) weighing 1,500 grams or less. The water is forced out by compressed air. It is an example of Newton's third law of motion.

Hello, I have just completed a build of a ServoChron altimeter with deploy servo and would like to verify the servo movement. Is it possible to cycle the servo through it's range of motion without drawing a vacuum in a chamber as shown in the bench test video?

It will travel 90° from its start position either clockwise or couterclockwise depending on which way you program it. I triggered mine by blowing air away from it to create a low pressure area, then stopping. If it is already loaded in your rocket, just cover up all but one air ports and then quickly inhale/exhale over the open one.

Niluht wrote:Hello, I have just completed a build of a ServoChron altimeter with deploy servo and would like to verify the servo movement. Is it possible to cycle the servo through it's range of motion without drawing a vacuum in a chamber as shown in the bench test video?

JT

Look in the manual for the section about configuring the deploy output. This is a permanent setting you can configure which will set the direction of the servo when deployed. If you go into the configuration mode for this setting (it involves pressing the MODE button while connecting the power) the servo will move back and forth from one limit to the opposite limit. You can then press the button again to set the servo to the preferred direction you want it to move when deployed. This is a good mode to test the movement of the servo with.

If you only want to verify the servo is working, a quick and dirty way to do that is to manually twist the servo to the deployed position and power up. The servo will move back to the armed position every time you power up and the servo is not already in that position.

Thanks for the replies! Yes, I did configure the servo direction as per the manual, but I think bugwubber's suggestion will allow me to check the deploy in the manner I was looking for. The instructions I followed were for the Launch Pad Altimetrer with one servo. Excited to try this, but waiting for some PL to cure...

Niluht wrote:Thanks for the replies! Yes, I did configure the servo direction as per the manual, but I think bugwubber's suggestion will allow me to check the deploy in the manner I was looking for. The instructions I followed were for the Launch Pad Altimetrer with one servo. Excited to try this, but waiting for some PL to cure...

Cheers, JT

If the goal is to test that the altimeter is going to deploy at apogee, then a easy way to test it is to drop the thing into a container or a drinking cup and make a vacuum with your mouth and cheeks covering the opening. On our rocket we test the whole deploy system on the ground by putting tape over all the pressure ports except one and then using a piece of rubber hose (or just bare lips) to suck the air on the one open pressure port. Using the hose is handy if the deploy has a rubber band that can hit you in the face when using bare lips!